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유전 센서 및 광섬유 센서를 이용한 EMC 유효 경화 수축 측정

Measurement of effective cure shrinkage of EMC using dielectric sensor and FBG sensor

  • 백정현 (한양대학교 융합기계공학과) ;
  • 박동운 (한양대학교 융합기계공학과) ;
  • 김학성 (한양대학교 융합기계공학과)
  • Baek, Jeong-hyeon (Department of Mechanical Convergence Engineering, Hanyang University) ;
  • Park, Dong-woon (Department of Mechanical Convergence Engineering, Hanyang University) ;
  • Kim, Hak-sung (Department of Mechanical Convergence Engineering, Hanyang University)
  • 투고 : 2022.12.18
  • 심사 : 2022.12.30
  • 발행 : 2022.12.30

초록

최근 반도체 패키지 두께가 점점 얇아짐에 따라 휨(warpage) 문제가 대두되고 있다. 휨(warpage)은 패키지 구성요소들 간의 물성 차이로 인해 발생하기 때문에, 휨(warpage)을 예측하기 위해서는 주된 구성요소인 EMC(Epoxy molding compound)의 정확한 물성 파악이 필수적으로 요구된다. 특히 EMC는 경화 공정 중 경화 수축을 보이는데, 겔점 이후에 발생하는 유효 경화 수축은 휨(warpage) 발생의 핵심 요소이다. 본 연구에서는 유전 센서를 이용해 측정한 소실 계수로부터 실제 반도체 패키지 경화 공정 동안 발생하는 EMC의 겔점이 정의되었다. 유전 센서로부터 얻은 결과를 분석하기 위해 DSC(Differential scanning calorimetry) 시험과 rheometer 시험이 수행되었다. 그 결과, 유전 측정법이 EMC 경화상태 모니터링에 효과적인 방법임이 검증되었다. 유전 측정과 동시에 광섬유 센서를 이용해 EMC의 경화 공정 중 변형률 변화 추이가 함께 측정되었다. 위 결과들로부터 경화 공정 중 발생하는 EMC의 유효 경화 수축이 측정되었다.

Recently, as the thickness of the semiconductor package becomes thinner, warpage has become a major issue. Since the warpage is caused by differences in material properties between package components, it is essential to precisely evaluate the material properties of the EMC(Epoxy molding compound), one of the main components, to predict the warpage accurately. Especially, the cure shrinkage of the EMC is generated during the curing process, and among them, the effective cure shrinkage that occurs after the gelation point is a key factor in warpage. In this study, the gelation point of the EMC was defined from the dissipation factor measured using the dielectric sensor during the curing process similar with actual semiconductor package. In addition, DSC (Differential scanning calorimetry) test and rheometer test were conducted to analyze the dielectrometry measurement. As a result, the dielectrometry was verified to be an effective method for monitoring the curing status of the EMC. Simultaneously, the strain transition of the EMC during the curing process was measured using the FBG (Fiber Bragg grating) sensor. From these results, the effective cure shrinkage of the EMC during the curing process was measured.

키워드

과제정보

This work was supported by Korea Institute of Energy Technology Evaluation and Planning(KETEP) grant funded by the Korea government(MOTIE)(20212020800090, Development and Demonstration of Energy-Efficiency Enhanced Technology for Temperature-Controlled Transportation and Logistics Center)

참고문헌

  1. W. K. Loh, R. Kulterman, H. Fu, and M. Tsuriya, "Recent trends of package warpage and measurement metrologies", 2016 International Conference on Electronics Packaging (ICEP), IEEE, pp. 89-93 (2016).
  2. N. Vijayaragavan, F. Carson, and A. Mistry, "Package on Package warpage-impact on surface mount yields and board level reliability", 2008 58th Electronic Components and Technology Conference, IEEE, pp. 389-396 (2008).
  3. M. J. Yim, R. Strode, R. Adimula, and C. Yoo, "Effects of material properties on PoP top package warpage behaviors", 2010 Proceedings 60th Electronic Components and Technology Conference (ECTC), IEEE, pp. 1071-1076 (2010).
  4. S. Phansalkar, C. Kim, and B. Han, "Why Is It Still Difficult to Make Accurate Prediction of the Warpage after Advanced Molding Processes?", 2021 IEEE 71st Electronic Components and Technology Conference (ECTC), IEEE, pp. 1505-1513 (2021).
  5. S. P. Phansalkar, C. Kim, B. Han, and P. J. Gromala, "Volumetric effective cure shrinkage measurement of dual curable adhesives by fiber Bragg grating sensor", Journal of Materials Science, 55(22), 9655-9664 (2020). https://doi.org/10.1007/s10853-020-04716-1
  6. H.-C. Cheng and Y.-C. Liu, "Warpage characterization of molded wafer for fan-out wafer-level packaging", Journal of Electronic Packaging, 142(1), 011004 (2020). https://doi.org/10.1115/1.4044625
  7. S. Han and K. Wang, "Integrated flow analysis during filling and post-filling stage of semiconductor encapsulation", J. Electron. Packag., 122(1), 20-27 (2000). https://doi.org/10.1115/1.483127
  8. S. Chao, Y. Liaw, and J.-H. Chou, "The effects of filler shape, type, and size on the properties of encapsulation molding components", Electronics, 10(2), 98 (2021). https://doi.org/10.3390/electronics10020098
  9. Y. Yang, G. Chiesura, G. Luyckx, T. Vervust, F. Bossuyt, M. Kaufmann, J. Degrieck, and J. Vanfleteren, "Development of a dielectric sensor system for the on-line cure monitoring of composites", Procedia Technology, 15, 631-637 (2014). https://doi.org/10.1016/j.protcy.2014.09.024
  10. D.-H. Kim and H.-S. Kim, "Smart cure cycle to improve tensile load capability of the adhesively bonded joint", Journal of Adhesion Science and Technology, 27(16), 1739-1754 (2013). https://doi.org/10.1080/01694243.2012.754317
  11. H. S. Kim, "Reduction of fabricational thermal residual stress of the hybrid co-cured structure using a dielectrometry", Composites Science and Technology, 67(1), 29-44 (2007). https://doi.org/10.1016/j.compscitech.2006.05.002
  12. Y. Wang, B. Han, D. Kim, A. Bar-Cohen, and P. Joseph, "Integrated measurement technique for curing process-dependent mechanical properties of polymeric materials using fiber bragg grating", Experimental Mechanics, 48(1), 107-117 (2008). https://doi.org/10.1007/s11340-007-9067-3
  13. G. M. Flockhart, R. R. Maier, J. S. Barton, W. N. MacPherson, J. D. Jones, K. E. Chisholm, L. Zhang, I. Bennion, I. Read, and P. D. Foote, "Quadratic behavior of fiber Bragg grating temperature coefficients", Applied Optics, 43(13), 2744-2751 (2004). https://doi.org/10.1364/AO.43.002744
  14. N. Tanaka, Y. Okabe, and N. Takeda, "Temperature-compensated strain measurement using fiber Bragg grating sensors embedded in composite laminates", Smart Materials and Structures, 12(6), 940 (2003). https://doi.org/10.1088/0964-1726/12/6/011
  15. C. Y. M. Tung and P. J. Dynes, "Relationship between viscoelastic properties and gelation in thermosetting systems", Journal of Applied Polymer Science, 27(2), 569-574 (1982). https://doi.org/10.1002/app.1982.070270220
  16. B.-S. Chiou, S. R. Raghavan, and S. A. Khan, "Effect of colloidal fillers on the cross-linking of a UV-curable polymer: gel point rheology and the winter- chambon criterion", Macromolecules, 34(13), 4526-4533 (2001). https://doi.org/10.1021/ma010281a
  17. C. Kim, S. P. Phansalkar, H. S. Lee, and B. Han, "Measurement of effective cure shrinkage of epoxy-based molding compound by fiber Bragg grating sensor using two-stage curing process", Journal of Applied Polymer Science, 139(6), 51620 (2022). https://doi.org/10.1002/app.51620